/** @file
  This is an implementation of the ACPI S3 Save protocol.  This is defined in
  S3 boot path specification 0.9.

Copyright (c) 2006 - 2019, Intel Corporation. All rights reserved.<BR>

SPDX-License-Identifier: BSD-2-Clause-Patent

**/

#include <PiDxe.h>
#include <Library/BaseMemoryLib.h>
#include <Library/UefiBootServicesTableLib.h>
#include <Library/PcdLib.h>
#include <Library/DebugLib.h>
#include <Protocol/AcpiS3Save.h>

#include "AcpiS3Save.h"

/**
  Hook point for AcpiVariableThunkPlatform for InstallAcpiS3Save.
**/
VOID
InstallAcpiS3SaveThunk (
  VOID
  );

/**
  Hook point for AcpiVariableThunkPlatform for S3Ready.

**/
VOID
S3ReadyThunkPlatform (
  VOID
  );

UINTN     mLegacyRegionSize;

EFI_ACPI_S3_SAVE_PROTOCOL mS3Save = {
  LegacyGetS3MemorySize,
  S3Ready,
};

/**
  Allocate memory below 4G memory address.

  This function allocates memory below 4G memory address.

  @param  MemoryType   Memory type of memory to allocate.
  @param  Size         Size of memory to allocate.

  @return Allocated address for output.

**/
VOID*
AllocateMemoryBelow4G (
  IN EFI_MEMORY_TYPE    MemoryType,
  IN UINTN              Size
  )
{
  UINTN                 Pages;
  EFI_PHYSICAL_ADDRESS  Address;
  EFI_STATUS            Status;
  VOID*                 Buffer;

  Pages = EFI_SIZE_TO_PAGES (Size);
  Address = 0xffffffff;

  Status  = gBS->AllocatePages (
                   AllocateMaxAddress,
                   MemoryType,
                   Pages,
                   &Address
                   );
  ASSERT_EFI_ERROR (Status);

  Buffer = (VOID *) (UINTN) Address;
  ZeroMem (Buffer, Size);

  return Buffer;
}

/**
  Gets the buffer of legacy memory below 1 MB
  This function is to get the buffer in legacy memory below 1MB that is required during S3 resume.

  @param This           A pointer to the EFI_ACPI_S3_SAVE_PROTOCOL instance.
  @param Size           The returned size of legacy memory below 1 MB.

  @retval EFI_SUCCESS           Size is successfully returned.
  @retval EFI_INVALID_PARAMETER The pointer Size is NULL.

**/
EFI_STATUS
EFIAPI
LegacyGetS3MemorySize (
  IN  EFI_ACPI_S3_SAVE_PROTOCOL   *This,
  OUT UINTN                       *Size
  )
{
  if (Size == NULL) {
    return EFI_INVALID_PARAMETER;
  }

  *Size = mLegacyRegionSize;
  return EFI_SUCCESS;
}

/**
  Prepares all information that is needed in the S3 resume boot path.

  Allocate the resources or prepare informations and save in ACPI variable set for S3 resume boot path

  @param This                 A pointer to the EFI_ACPI_S3_SAVE_PROTOCOL instance.
  @param LegacyMemoryAddress  The base address of legacy memory.

  @retval EFI_NOT_FOUND         Some necessary information cannot be found.
  @retval EFI_SUCCESS           All information was saved successfully.
  @retval EFI_OUT_OF_RESOURCES  Resources were insufficient to save all the information.
  @retval EFI_INVALID_PARAMETER The memory range is not located below 1 MB.

**/
EFI_STATUS
EFIAPI
S3Ready (
  IN EFI_ACPI_S3_SAVE_PROTOCOL    *This,
  IN VOID                         *LegacyMemoryAddress
  )
{
  STATIC BOOLEAN                  AlreadyEntered;

  DEBUG ((EFI_D_INFO, "S3Ready!\n"));

  //
  // Platform may invoke AcpiS3Save->S3Save() before ExitPmAuth, because we need save S3 information there, while BDS ReadyToBoot may invoke it again.
  // So if 2nd S3Save() is triggered later, we need ignore it.
  //
  if (AlreadyEntered) {
    return EFI_SUCCESS;
  }
  AlreadyEntered = TRUE;

  return EFI_SUCCESS;
}

/**
  The Driver Entry Point.

  The function is the driver Entry point which will produce AcpiS3SaveProtocol.

  @param ImageHandle   A handle for the image that is initializing this driver
  @param SystemTable   A pointer to the EFI system table

  @retval EFI_SUCCESS               Driver initialized successfully
  @retval EFI_UNSUPPORTED           Do not support ACPI S3
  @retval EFI_OUT_OF_RESOURCES      Could not allocate needed resources

**/
EFI_STATUS
EFIAPI
InstallAcpiS3Save (
  IN EFI_HANDLE           ImageHandle,
  IN EFI_SYSTEM_TABLE     *SystemTable
  )
{
  EFI_STATUS        Status;

  if (!PcdGetBool (PcdAcpiS3Enable)) {
    return EFI_UNSUPPORTED;
  }

  if (!FeaturePcdGet(PcdPlatformCsmSupport)) {
    //
    // More memory for no CSM tip, because GDT need relocation
    //
    mLegacyRegionSize = 0x250;
  } else {
    mLegacyRegionSize = 0x100;
  }

  Status = gBS->InstallProtocolInterface (
                  &ImageHandle,
                  &gEfiAcpiS3SaveProtocolGuid,
                  EFI_NATIVE_INTERFACE,
                  &mS3Save
                  );
  ASSERT_EFI_ERROR (Status);
  return Status;
}
